1912] Esterly: Copepoda of the San Diego Region 297 
most abundantly at the surface within the same four hours 
of the evening. 
It is difficult to say whether the irregular occurrence of 
Eucalanus at the surface is due to lack of hauling at certain 
times or to the habit of the species. There is no reason to feel 
that the curve for Hucalanus must resemble that for Calanus, 
yet it might if more hauls were available. The afternoon, even- 
ing and morning maxima shown in figure 2 are probably of 
normal occurrence; they should be so considered at this time, 
at any rate. 
The distribution of Hucalanus as shown by the horizontal 
closing nets will not be considered here, since that was done 
in another paper (Hsterly, 19lla). There appears to be an 
extensive movement of the species below the surface, but it 
ean hardly be called an upward migration such as is so evident 
for Calanus. The daylight plurimum of Eucalanus as shown 
by the horizontal nets is at 200 fathoms. 
The occurrence of Eucalanus as shown by hauls with the 
vertical closing nets is given in table 23 which follows. It is 
similar to table 14 for Calanus. 
TABLE 23 
Distribution of HYucalanus as shown by the vertical closing nets 
Day Night 
6-12 a.m., 4-6 p.m. 2-6 a.m., 6-8 p.m. (below 50 f.) 
Depth in Hauls Animals Hauls Animals 
fathoms Total Success. Total Per fath. Freq. Total Success. Total Per fath. Freq. 
: 5-0 15 0 0 0.6 0 14 4 6 1.2 29 
2. 10-5 15 3 cata 2.0 20 14 8 suit 2.2 52 
3. 15-10 15 4 5 1.6 27 15 9 19 3.7 60 
4. 20-15 15 5 18 3.6 33 15 12 21 4.2 80 
5. 25-20 15 10 32 6.4 66 14 11 44 8.8 78 
6. 30-25 17 11 46 9.5 65 14 3 30 6.0 93 
7. 40-80 14 10 38 3.8 72 14 12 42 4.2 81 
8. 50-40 16 12 52 2.6 66 15 13 65 6.5 82 
9. 75-50 17 12 84 3) 70 16 12 48 1g 66 
10. 100-75 
11. 150-100 
6 f 0.16 33 
6 
12. 200-150 6 
6 
4 
1 
Seco) 1.6 75 
3 620 0.4 100 
13. 250-200 1 
14. 300-250 1 
1 0.02 100 
1 0.02 100 
